Perhaps you should try some spelling variations:
sach ky » sac ky, sach y, sach ty
dao huu » do huu
dao suu » da suu
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
xuc va » duc va, tuc va, xac va
va cao » va cac, va co, va dao
luc va » duc va, tuc va, loc va

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky tang xa hoi. hieu va cao ((xuc va) OR (luc va)) lanh ((dao suu) OR (dao huu)) viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky tang xa hoi. hieu va cao ((xuc va) or (luc va)) lanh ((dao suu) OR (dao huu)) viet~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky tang xa hoi. hieu va cao ((xuc va) or (luc va)) lanh ((dao suu) OR (dao huu)) viet*.